A property listing is not free-form text. Once an energy certificate exists for the building, Section 87 subsection 1 of the German Building Modernisation Act requires five disclosures in the listing (GModG) — on your own website just as in any other commercial medium. If one of them is missing, that is a regulatory offence carrying a maximum of ten thousand euros (GModG). This article shows which disclosures are meant, when the duty does not apply, how photos and floor plans reach the page cleanly, and what a listing page looks like that convinces buyers and survives an inspection.
What a property listing has to contain
Germany had around 44.0 million dwellings at the end of 2025 (Statistisches Bundesamt). The 13.5 million single-family homes account for just under a third of all dwellings in residential buildings (Statistisches Bundesamt), and an average dwelling measures 94.0 square metres (Statistisches Bundesamt). Those figures say little about any single mandate, but a lot about the way the work runs: anyone brokering property publishes tens or hundreds of listings a year, and every one of them carries the same duties. A mistake in the template is therefore not one case but a whole series.
The central provision is Section 87 subsection 1 of the German Building Modernisation Act, which was called the Buildings Energy Act before it was renamed. It hinges on two conditions: a property listing is placed in commercial media before a sale, letting, lease or leasing arrangement, and an energy certificate exists at that point. If both are true, the person responsible for the publication — seller, landlord, lessor, leasing provider or estate agent — has to make sure the listing contains five disclosures (GModG). Your own website is no special case here. It is a commercial medium like any listing page, and it is where most prospects see the property first.
The five disclosures are the type of energy certificate, meaning a demand-based or a consumption-based one; the value for final energy demand or final energy consumption stated in the certificate; the main energy sources used for heating as stated in the certificate; and, for a residential building, the year of construction and the energy efficiency class given in the certificate (GModG). The law does not prescribe how these fields look — they have to be recognisably part of the listing and must not sit on some remote subpage. Anyone building listing pages on a fixed field set solves this once and has it handled for every new property afterwards. The article on legal pages such as the imprint and privacy policy describes the same principle: mandatory content belongs in the structure, not in one person’s diligence.
When the duty actually applies
The most common misreading treats Section 87 as a standalone duty to obtain a certificate. The wording says otherwise: the five disclosures fall due when an energy certificate already exists at the time of the listing (GModG). Whether one has to exist at all is settled one provision earlier. Under Section 80 subsection 3 GModG an energy certificate has to be issued on sale and on letting unless a valid one is already in place. For residential buildings with fewer than five dwellings whose building application was filed before 1 November 1977, a demand-based certificate has to be issued (GModG) — unless the building already met the 1977 thermal insulation standard on completion or was brought up to it later.
The duty hangs on the existing certificate
The five disclosures one by one
Each of the five disclosures has exactly one source: the energy certificate itself. None of it is estimated, converted or derived from an old heating bill. Anyone transferring the values into the listing template should record the issue date at the same time. It decides later whether the listing still holds, and it shows which part of the portfolio needs updating soon.
Type of certificate
Demand-based or consumption-based, exactly as it was issued. Both types are permitted, but they are not interchangeable and rest on very different foundations.
Final energy value
The final energy demand or final energy consumption stated in the certificate, in kilowatt hours per square metre and year, taken over unchanged.
Main energy sources
The energy sources for heating named in the certificate, such as natural gas, district heating or electricity for a heat pump.
Year of construction
Only for a residential building, and only the year of construction stated in the certificate, not the year of a later refurbishment.
Energy efficiency class
Also only for a residential building, from A+ to H, exactly as the energy certificate shows it.
Non-residential buildings
Here heat and electricity replace the single final energy value (GModG), while year of construction and efficiency class drop out.
That last point is rarely observed in practice. For a non-residential building, the final energy demand or consumption has to be stated for heat and for electricity separately (GModG). A warehouse, a retail unit or an office floor therefore needs two values in the listing instead of one. Anyone running residential and commercial properties on the same website needs two field sets and a switch between them — the same idea the article on private and business customers on one website describes for the wording.
Scroll table sideways
| Property type | Disclosures in the listing | Particularity |
|---|---|---|
| Residential building | Certificate type, final energy value, energy sources, year of construction, efficiency class | five disclosures once a certificate exists |
| Non-residential building | Certificate type, final energy for heat and electricity separately, energy sources | year of construction and efficiency class drop out |
| Certificate from 2007 to 2014 | Disclosures under Section 112 subsections 3 and 4 GModG | transitional rule for older certificates |
| Small building | no disclosures from an energy certificate | exempt from the certificate rules |
| Listed monument | disclosures only if a certificate exists | no duty to issue one on sale |
Exemptions, old certificates and non-residential buildings
Three rules shift the picture, and none of them sits in Section 87. First: the provisions on energy certificates do not apply to a small building (GModG), and a small building is one with no more than 50 square metres of usable floor area (GModG). Second: Section 80 subsections 3 to 7 GModG does not apply to a listed monument, so there is no duty to issue a certificate for a sale or a letting — but if one exists anyway, the listing duties apply unchanged. Third: for certificates issued after 30 September 2007 and before 1 May 2014, the duties follow Section 112 subsections 3 and 4 GModG (GModG). Anyone holding one of these three constellations should model it in the listing template rather than re-assess it every time.
- An energy certificate is issued for a validity period of ten years (GModG) — after that a listing carries outdated values.
- A consumption-based certificate rests on bills covering a continuous period of 36 months whose most recent billing period may not be more than 18 months in the past (GModG).
- A certificate can become unusable earlier if a change to the building makes a new one necessary.
- Sellers and estate agents have to present the certificate or a copy at the viewing at the latest (GModG).
- Where no viewing takes place, the certificate belongs in the prospect’s hands without delay.
- Failing to ensure the disclosures is a regulatory offence, not a trivial slip: it is a named statutory case.
The range for it sits in Section 108 GModG. Subsection 1 no. 21 names the case expressly: anyone who, contrary to Section 87 subsection 1, fails to ensure that the property listing contains the disclosures named there commits a regulatory offence (GModG). Subsection 2 no. 2 assigns that case to the middle tier, meaning a fine of up to ten thousand euros (GModG). For a business with many properties this is less a cost risk than a process risk: the mistake repeats with every property entered on the same pattern. That is exactly why the check belongs in the template and not in a final review; how such templates come about is set out under features around website and structure.
Photos and floor plans: who owns the motif
Property photos are the second area where listings become vulnerable. A photograph is protected even without artistic ambition: the right in it expires fifty years after the photograph is published (UrhG). For photographic works and for the building itself the long term applies — copyright expires seventy years after the death of the author (UrhG). A house from the 1980s is therefore still protected as a rule, and that covers the architecture as much as the floor plan behind it.
- Shots from the pavement: freedom of panorama covers works permanently located on public ways, streets or squares — for buildings these powers extend only to the external appearance (UrhG).
- Interior shots are not covered; they need the consent of the rights holders and of any people shown.
- Drone images are not taken from a public way and can hardly be based on freedom of panorama.
- Floor plans and elevations are works in their own right; the usage rights come from the planner or surveyor, not automatically from the owner.
- With commissioned photographers, the scope of use belongs in the brief: website, portals, print display, duration, transfer.
- People in the picture need consent, even when they are only crossing the street in the background.
One image credit per property
Commission, text form and company details
Anyone writing about commission on the website is moving through two separate sets of rules. For the purchase of a flat or a single-family house, the agency agreement requires text form (BGB). If the agent takes a promise of commission from both parties to the purchase contract, this can only be done in such a way that the parties commit in equal amounts (BGB). And where only one party has entered into the agency agreement, an arrangement obliging the other party to pay or reimburse commission is only valid if the party that concluded the agreement remains liable for at least the same amount (BGB). A listing page that speaks of shared commission should therefore reflect exactly that.
For letting residential space a different act applies. The letting agent may not demand a fee from the flat seeker unless the agent obtains the mandate from the landlord exclusively because of that brokerage agreement (WoVermRG). And the amount is capped: the fee may not exceed two months’ rent plus statutory value added tax (WoVermRG). A commission statement on a listing page should therefore say which case it refers to; a blanket line above all properties is wrong more often than not. How price statements hold up in general is shown by the article on pricing and advertising claims.
The letting agent may not demand, accept a promise of, or accept a fee from the flat seeker for brokering or evidencing an opportunity to conclude tenancy agreements for residential space, unless the letting agent obtains the mandate to offer the flat from the landlord or another authorised person exclusively because of the brokerage agreement with the flat seeker.
Building the listing page cleanly
A listing page is a data page at heart. It consists of a few fixed fields that are named the same for every property, and of varying text around them. If the mandatory fields are part of the template, a property cannot be published without them — the mistake is ruled out by construction instead of being searched for afterwards. That is the same idea as with structured data for search results: fixed fields, reliable output, no manual work in the individual case.
- A mandatory field block for the energy certificate data, visible on the listing page and on the overview card.
- A property type field that switches between residential and non-residential and swaps the fields accordingly.
- A date field for the issue of the certificate so that the ten years stay traceable.
- An image area where the provenance has to be recorded for every picture before it goes live.
- A contact route directly on the property so the enquiry does not travel via the home page — see contact forms that turn visitors into leads.
- A document area for the brochure and the certificate copy, see downloads and PDF documents on the website.
The website also needs the company details. Brokering contracts over land and residential space requires a licence under Section 34c subsection 1 of the German Trade Regulation Act. Because the activity therefore requires official authorisation, the German Digital Services Act additionally requires details of the competent supervisory authority in the imprint (DDG). Anyone forgetting that line leaves an easily discoverable defect on the site. And because every listing page processes personal data of prospects, it is worth reading the article on answering a GDPR subject access request as well; examples of how such pages are built are in the demos.
What the business takes away
The mandatory disclosures are not a side issue but the part of a listing page that is easiest to check — by prospects and by authorities alike. They cost effort once in the template and nothing afterwards. Everything else running through this article follows the same pattern: image provenance, commission statement and supervisory authority belong in a fixed field rather than in someone’s memory. How a website like that comes together is described on how it works.
Anyone wanting to review their own listings takes three existing ones and works through the energy certificate data, then the image provenance, then the commission line. What surfaces is usually a pattern rather than a one-off. For the quieter weeks in which exactly this kind of work fits, the article on fewer enquiries and the website in a quiet period describes an approach; how an emergency topic gets the same structure is shown by the article on the roofer website with storm damage and emergency service.
Sources and Studies